(1) Field of the Invention
The present invention relates to a valve timing control apparatus for an internal combustion engine which controls valve open-and-closure characteristics of an intake valve(s) or an exhaust valve(s) of the internal combustion engine.
(2) Description of Related Art
Recently, a valve timing control apparatus has been proposed in which a phase modification mechanism which converts a relative rotational phase of a camshaft with respect to a sprocket to which a rotational force from a crankshaft is transmitted by transmitting a rotational force of an electrically driven motor to a camshaft which provides an output axle via a speed reduction mechanism to control open-and-closure timings of an intake valve(s) and/or an exhaust valve(s).
Such a valve timing control apparatus as described above is exemplified by a Japanese Patent Application First Publication No. 2011-256798 published on Dec. 22, 2011 in which a power supply to the electrically driven motor is carried out by means of an electrical contact between a brush mounted on a cover member arranged at a forward side of the phase modification mechanism and a slip ring installed at the phase modification mechanism side.